Why is measuring strawberry leaves important?

Experienced agronomists can confirm: measuring strawberry leaves is an important part of agronomy because it can provide a wealth of information about the plant’s growth and health, which can be used to optimize crop yield and quality. The main information which we can get with data about the strawberry plants is:

1. Nutrient uptake: The size and color of the leaves can indicate the plant’s overall health and well-being, as well as provide insight into how well the plant is absorbing nutrients from the soil. For example, if the leaves are yellowing, it may indicate a lack of nitrogen, while small, pale leaves can indicate a lack of light.
2. Water stress: Measuring the size of the leaves can also provide information about the amount of water the plant is receiving. If the leaves are small and dry, it may indicate that the plant is not getting enough water. This can be important information for determining irrigation needs.
3. Disease and pest management: Measuring the leaves can also provide information about the presence of disease or pests. For example, if the leaves have holes or brown spots, it may indicate that the plant is being attacked by pests or diseases.
4. Yield prediction: We have already written about this aspect but briefly speaking: measurement of the leaf area can give us an estimation of the plant growth and future yield, making it possible to plan the harvest in advance
5. Light interception: The leaf area measurement give us an estimation of the plant capability of capturing light energy, this is important in prediction of yield and also to make decision in terms of light management

How to measure strawberry leaves?

There are a few different ways to measure the size and area of strawberry leaves, both destructively and non-destructively.

A destructive method for measuring the size of a strawberry leaf would involve cutting the leaf off of the plant and then measuring its length and width using a ruler or a digital tool like a smartphone app. To measure the area, you would use a scanner with software like ImajeJ. However, this requires extra time for preparation and scanning of the leaves.

Otherwise, a smartphone application can determine the area of the leaf in faster way with the same accuracy as software for desktop computers

Non-destructive measurement of trifoliate strawberry leaves

A non-destructive method for measuring the size of a strawberry leaf would involve measuring the leaf while it is still attached to the plant. This can be done using a variety of leaf area meters. For example, there are laser, optical and digital leaf area meters. Laser or optical leaf area meter projects a beam of light onto the leaf and measures the amount of light that is reflected back. This information is used to calculate the leaf area.

Digital leaf area meters use an image of a leaf taken with a digital camera, and analyze the image to recognize the shape and size of the leaf. They calculate the leaf area by determining the number of pixels that fall within the leaf’s contour, and then converting that measurement to square centimeters.

This would allow you to measure the leaf area without too active physically handling the leaf, which can be beneficial for delicate leaves or for measuring multiple leaves.

Alternatively, it is possible to manually measure the leaf area with a grid sheet (millimetre paper).

Non-destructive measurement of strawberry canopy

Finally, a non-destructive method for measuring the area of strawberry leaves can also be done by using a technique called ‘digital canopy analysis’ which uses an overhead camera to take pictures of a strawberry plant to process those pictures in order to extract information about the amount of green biomass.

It’s important to note that, depending on the technique or the equipment used, there can be a certain level of accuracy and precision error, so it’s important to be familiar with the equipment and method used, to get the best possible results.

Can Petiole Pro measure leaf area of strawberry leaves (trifoliate)?

The short answer is “yes”, it is possible for the mobile application Petiole Pro to measure the leaf area of strawberry leaves.

Petiole Pro can measure leaf are of strawberry leaves (trifoliate) in destructive and non-destructive way. It also can be exploited for digital canopy analysis of strawberry crops

However, the accuracy of the measurement may vary depending on certain factors.

• If measuring strawberry leaf area non-destructively and the petioles are long enough, the full trifoliate without cutting it into pieces may provide the most accurate results.
• In cases where leaves have already been cut out of the plant and there are minimal visual distractions such as shadows during measurement, then measuring the entire trifoliate as one piece may still yield acceptable results.
• When the trifoliate is too large to fit within the camera’s focus, it is recommended to cut it into smaller pieces. This means it is possible to measure the leaf area of each piece separately, before summing up the measurements, this will ensure accurate results.

Overall, the ability to measure the leaf area of a trifoliate with Petiole Pro will depend on the variety of strawberries, size of trifoliate, stage of plant development and place where the measurements are made.

Which calibration pad to use when measuring strawberries with Petiole Pro?

When using Petiole Pro to measure strawberry leaves, it’s important to use the right calibration pad. One way to determine which calibration pad to use is by doing a quick visual check. You can do this by placing your smartphone on a measuring stand or height of around 20 cm and then checking if you can see the strawberry leaf through the camera. You can do this by simply opening the camera app and looking at the screen. If the leaf fits on the screen, then the height is correct and you can proceed to the next step.

If the leaf is not fully visible, you may need to place the smartphone a bit higher to capture the full leaf.

Once you have the right height for your camera you can try with calibration pad no. 6 or 7. These pads should fit the screen completely. If the message “Camera is calibrated” appears then you can start measuring the leaves. If the camera can not capture the full size of the pad, you may need to use the calibration pad no.8 which is currently the largest one.

In short, to select the right calibration pad for Petiole Pro, you should check if the leaf fits on the camera, adjust your camera height if needed, try the smaller calibration pad first, if the screen does not fully cover the pad, use the bigger one till the message “Camera is calibrated” is shown.